1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
7 * This file is part of the SCTP kernel implementation
9 * This SCTP implementation is free software;
10 * you can redistribute it and/or modify it under the terms of
11 * the GNU General Public License as published by
12 * the Free Software Foundation; either version 2, or (at your option)
15 * This SCTP implementation is distributed in the hope that it
16 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
17 * ************************
18 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
19 * See the GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with GNU CC; see the file COPYING. If not, see
23 * <http://www.gnu.org/licenses/>.
25 * Please send any bug reports or fixes you make to the
27 * lksctp developers <linux-sctp@vger.kernel.org>
29 * Written or modified by:
30 * Randall Stewart <randall@sctp.chicago.il.us>
31 * Ken Morneau <kmorneau@cisco.com>
32 * Qiaobing Xie <qxie1@email.mot.com>
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Jon Grimm <jgrimm@us.ibm.com>
36 * Xingang Guo <xingang.guo@intel.com>
37 * Hui Huang <hui.huang@nokia.com>
38 * Sridhar Samudrala <sri@us.ibm.com>
39 * Daisy Chang <daisyc@us.ibm.com>
40 * Dajiang Zhang <dajiang.zhang@nokia.com>
41 * Ardelle Fan <ardelle.fan@intel.com>
42 * Ryan Layer <rmlayer@us.ibm.com>
43 * Anup Pemmaiah <pemmaiah@cc.usu.edu>
44 * Kevin Gao <kevin.gao@intel.com>
47 #ifndef __sctp_structs_h__
48 #define __sctp_structs_h__
50 #include <linux/ktime.h>
51 #include <linux/rhashtable.h>
52 #include <linux/socket.h> /* linux/in.h needs this!! */
53 #include <linux/in.h> /* We get struct sockaddr_in. */
54 #include <linux/in6.h> /* We get struct in6_addr */
55 #include <linux/ipv6.h>
56 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */
57 #include <linux/atomic.h> /* This gets us atomic counters. */
58 #include <linux/skbuff.h> /* We need sk_buff_head. */
59 #include <linux/workqueue.h> /* We need tq_struct. */
60 #include <linux/sctp.h> /* We need sctp* header structs. */
61 #include <net/sctp/auth.h> /* We need auth specific structs */
62 #include <net/ip.h> /* For inet_skb_parm */
64 /* A convenience structure for handling sockaddr structures.
65 * We should wean ourselves off this.
68 struct sockaddr_in v4;
69 struct sockaddr_in6 v6;
73 /* Forward declarations for data structures. */
76 struct sctp_association;
77 struct sctp_transport;
82 struct sctp_bind_addr;
84 struct sctp_ep_common;
89 #include <net/sctp/tsnmap.h>
90 #include <net/sctp/ulpevent.h>
91 #include <net/sctp/ulpqueue.h>
92 #include <net/sctp/stream_interleave.h>
94 /* Structures useful for managing bind/connect. */
96 struct sctp_bind_bucket {
98 unsigned short fastreuse;
99 struct hlist_node node;
100 struct hlist_head owner;
104 struct sctp_bind_hashbucket {
106 struct hlist_head chain;
109 /* Used for hashing all associations. */
110 struct sctp_hashbucket {
112 struct hlist_head chain;
113 } __attribute__((__aligned__(8)));
116 /* The SCTP globals structure. */
117 extern struct sctp_globals {
118 /* This is a list of groups of functions for each address
119 * family that we support.
121 struct list_head address_families;
123 /* This is the hash of all endpoints. */
124 struct sctp_hashbucket *ep_hashtable;
125 /* This is the sctp port control hash. */
126 struct sctp_bind_hashbucket *port_hashtable;
127 /* This is the hash of all transports. */
128 struct rhltable transport_hashtable;
130 /* Sizes of above hashtables. */
134 /* Default initialization values to be applied to new associations. */
136 __u16 max_outstreams;
138 /* Flag to indicate whether computing and verifying checksum
140 bool checksum_disable;
143 #define sctp_max_instreams (sctp_globals.max_instreams)
144 #define sctp_max_outstreams (sctp_globals.max_outstreams)
145 #define sctp_address_families (sctp_globals.address_families)
146 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
147 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
148 #define sctp_port_hashsize (sctp_globals.port_hashsize)
149 #define sctp_port_hashtable (sctp_globals.port_hashtable)
150 #define sctp_transport_hashtable (sctp_globals.transport_hashtable)
151 #define sctp_checksum_disable (sctp_globals.checksum_disable)
153 /* SCTP Socket type: UDP or TCP style. */
154 enum sctp_socket_type {
156 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
160 /* Per socket SCTP information. */
162 /* inet_sock has to be the first member of sctp_sock */
163 struct inet_sock inet;
164 /* What kind of a socket is this? */
165 enum sctp_socket_type type;
167 /* PF_ family specific functions. */
170 /* Access to HMAC transform. */
171 struct crypto_shash *hmac;
174 /* What is our base endpointer? */
175 struct sctp_endpoint *ep;
177 struct sctp_bind_bucket *bind_hash;
178 /* Various Socket Options. */
179 __u16 default_stream;
182 __u32 default_context;
183 __u32 default_timetolive;
184 __u32 default_rcv_context;
187 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
188 * the destination address every heartbeat interval. This value
189 * will be inherited by all new associations.
193 /* This is the max_retrans value for new associations. */
196 /* The initial Path MTU to use for new associations. */
199 /* The default SACK delay timeout for new associations. */
203 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
206 struct sctp_rtoinfo rtoinfo;
207 struct sctp_paddrparams paddrparam;
208 struct sctp_assocparams assocparams;
211 * These two structures must be grouped together for the usercopy
214 struct sctp_event_subscribe subscribe;
215 struct sctp_initmsg initmsg;
220 __u32 adaptation_ind;
229 data_ready_signalled:1;
232 /* Receive to here while partial delivery is in effect. */
233 struct sk_buff_head pd_lobby;
235 /* These must be the last fields, as they will skipped on copies,
236 * like on accept and peeloff operations
238 struct list_head auto_asconf_list;
242 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
244 return (struct sctp_sock *)sk;
247 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
249 return (struct sock *)sp;
252 #if IS_ENABLED(CONFIG_IPV6)
254 struct sctp_sock sctp;
255 struct ipv6_pinfo inet6;
257 #endif /* CONFIG_IPV6 */
260 /* This is our APPLICATION-SPECIFIC state cookie.
261 * THIS IS NOT DICTATED BY THE SPECIFICATION.
263 /* These are the parts of an association which we send in the cookie.
264 * Most of these are straight out of:
265 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
271 /* My : Tag expected in every inbound packet and sent
272 * Verification: in the INIT or INIT ACK chunk.
277 /* Peer's : Tag expected in every outbound packet except
278 * Verification: in the INIT chunk.
283 /* The rest of these are not from the spec, but really need to
287 /* My Tie Tag : Assist in discovering a restarting association. */
290 /* Peer's Tie Tag: Assist in discovering a restarting association. */
293 /* When does this cookie expire? */
296 /* Number of inbound/outbound streams which are set
297 * and negotiated during the INIT process.
299 __u16 sinit_num_ostreams;
300 __u16 sinit_max_instreams;
302 /* This is the first sequence number I used. */
305 /* This holds the originating address of the INIT packet. */
306 union sctp_addr peer_addr;
309 * Include the source port of the INIT-ACK
315 /* Padding for future use */
318 __u32 adaptation_ind;
320 __u8 auth_random[sizeof(struct sctp_paramhdr) +
321 SCTP_AUTH_RANDOM_LENGTH];
322 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
323 __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
325 /* This is a shim for my peer's INIT packet, followed by
326 * a copy of the raw address list of the association.
327 * The length of the raw address list is saved in the
328 * raw_addr_list_len field, which will be used at the time when
329 * the association TCB is re-constructed from the cookie.
331 __u32 raw_addr_list_len;
332 struct sctp_init_chunk peer_init[0];
336 /* The format of our cookie that we send to our peer. */
337 struct sctp_signed_cookie {
338 __u8 signature[SCTP_SECRET_SIZE];
339 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
340 struct sctp_cookie c;
343 /* This is another convenience type to allocate memory for address
344 * params for the maximum size and pass such structures around
347 union sctp_addr_param {
348 struct sctp_paramhdr p;
349 struct sctp_ipv4addr_param v4;
350 struct sctp_ipv6addr_param v6;
353 /* A convenience type to allow walking through the various
354 * parameters and avoid casting all over the place.
358 struct sctp_paramhdr *p;
359 struct sctp_cookie_preserve_param *life;
360 struct sctp_hostname_param *dns;
361 struct sctp_cookie_param *cookie;
362 struct sctp_supported_addrs_param *sat;
363 struct sctp_ipv4addr_param *v4;
364 struct sctp_ipv6addr_param *v6;
365 union sctp_addr_param *addr;
366 struct sctp_adaptation_ind_param *aind;
367 struct sctp_supported_ext_param *ext;
368 struct sctp_random_param *random;
369 struct sctp_chunks_param *chunks;
370 struct sctp_hmac_algo_param *hmac_algo;
371 struct sctp_addip_param *addip;
374 /* RFC 2960. Section 3.3.5 Heartbeat.
375 * Heartbeat Information: variable length
376 * The Sender-specific Heartbeat Info field should normally include
377 * information about the sender's current time when this HEARTBEAT
378 * chunk is sent and the destination transport address to which this
379 * HEARTBEAT is sent (see Section 8.3).
381 struct sctp_sender_hb_info {
382 struct sctp_paramhdr param_hdr;
383 union sctp_addr daddr;
384 unsigned long sent_at;
388 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
390 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
391 void sctp_stream_free(struct sctp_stream *stream);
392 void sctp_stream_clear(struct sctp_stream *stream);
393 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
395 /* What is the current SSN number for this stream? */
396 #define sctp_ssn_peek(stream, type, sid) \
397 ((stream)->type[sid].ssn)
399 /* Return the next SSN number for this stream. */
400 #define sctp_ssn_next(stream, type, sid) \
401 ((stream)->type[sid].ssn++)
403 /* Skip over this ssn and all below. */
404 #define sctp_ssn_skip(stream, type, sid, ssn) \
405 ((stream)->type[sid].ssn = ssn + 1)
407 /* What is the current MID number for this stream? */
408 #define sctp_mid_peek(stream, type, sid) \
409 ((stream)->type[sid].mid)
411 /* Return the next MID number for this stream. */
412 #define sctp_mid_next(stream, type, sid) \
413 ((stream)->type[sid].mid++)
415 /* Skip over this mid and all below. */
416 #define sctp_mid_skip(stream, type, sid, mid) \
417 ((stream)->type[sid].mid = mid + 1)
419 #define sctp_stream_in(asoc, sid) (&(asoc)->stream.in[sid])
421 /* What is the current MID_uo number for this stream? */
422 #define sctp_mid_uo_peek(stream, type, sid) \
423 ((stream)->type[sid].mid_uo)
425 /* Return the next MID_uo number for this stream. */
426 #define sctp_mid_uo_next(stream, type, sid) \
427 ((stream)->type[sid].mid_uo++)
430 * Pointers to address related SCTP functions.
431 * (i.e. things that depend on the address family.)
434 int (*sctp_xmit) (struct sk_buff *skb,
435 struct sctp_transport *);
436 int (*setsockopt) (struct sock *sk,
440 unsigned int optlen);
441 int (*getsockopt) (struct sock *sk,
446 int (*compat_setsockopt) (struct sock *sk,
450 unsigned int optlen);
451 int (*compat_getsockopt) (struct sock *sk,
456 void (*get_dst) (struct sctp_transport *t,
457 union sctp_addr *saddr,
460 void (*get_saddr) (struct sctp_sock *sk,
461 struct sctp_transport *t,
463 void (*copy_addrlist) (struct list_head *,
464 struct net_device *);
465 int (*cmp_addr) (const union sctp_addr *addr1,
466 const union sctp_addr *addr2);
467 void (*addr_copy) (union sctp_addr *dst,
468 union sctp_addr *src);
469 void (*from_skb) (union sctp_addr *,
472 void (*from_sk) (union sctp_addr *,
474 void (*from_addr_param) (union sctp_addr *,
475 union sctp_addr_param *,
476 __be16 port, int iif);
477 int (*to_addr_param) (const union sctp_addr *,
478 union sctp_addr_param *);
479 int (*addr_valid) (union sctp_addr *,
481 const struct sk_buff *);
482 enum sctp_scope (*scope)(union sctp_addr *);
483 void (*inaddr_any) (union sctp_addr *, __be16);
484 int (*is_any) (const union sctp_addr *);
485 int (*available) (union sctp_addr *,
487 int (*skb_iif) (const struct sk_buff *sk);
488 int (*is_ce) (const struct sk_buff *sk);
489 void (*seq_dump_addr)(struct seq_file *seq,
490 union sctp_addr *addr);
491 void (*ecn_capable)(struct sock *sk);
492 __u16 net_header_len;
494 sa_family_t sa_family;
495 struct list_head list;
498 struct sctp_af *sctp_get_af_specific(sa_family_t);
499 int sctp_register_af(struct sctp_af *);
501 /* Protocol family functions. */
503 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
504 void (*skb_msgname) (struct sk_buff *, char *, int *);
505 int (*af_supported) (sa_family_t, struct sctp_sock *);
506 int (*cmp_addr) (const union sctp_addr *,
507 const union sctp_addr *,
509 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
510 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
511 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
512 struct sock *(*create_accept_sk) (struct sock *sk,
513 struct sctp_association *asoc,
515 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
516 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
517 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
522 /* Structure to track chunk fragments that have been acked, but peer
523 * fragments of the same message have not.
525 struct sctp_datamsg {
526 /* Chunks waiting to be submitted to lower layer. */
527 struct list_head chunks;
528 /* Reference counting. */
530 /* When is this message no longer interesting to the peer? */
531 unsigned long expires_at;
532 /* Did the messenge fail to send? */
535 can_delay:1, /* should this message be Nagle delayed */
536 abandoned:1; /* should this message be abandoned */
539 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
540 struct sctp_sndrcvinfo *,
542 void sctp_datamsg_free(struct sctp_datamsg *);
543 void sctp_datamsg_put(struct sctp_datamsg *);
544 void sctp_chunk_fail(struct sctp_chunk *, int error);
545 int sctp_chunk_abandoned(struct sctp_chunk *);
547 /* RFC2960 1.4 Key Terms
549 * o Chunk: A unit of information within an SCTP packet, consisting of
550 * a chunk header and chunk-specific content.
552 * As a matter of convenience, we remember the SCTP common header for
553 * each chunk as well as a few other header pointers...
556 struct list_head list;
560 /* How many times this chunk have been sent, for prsctp RTX policy */
564 /* This is our link to the per-transport transmitted list. */
565 struct list_head transmitted_list;
566 /* List in specific stream outq */
567 struct list_head stream_list;
570 /* This field is used by chunks that hold fragmented data.
571 * For the first fragment this is the list that holds the rest of
572 * fragments. For the remaining fragments, this is the link to the
573 * frag_list maintained in the first fragment.
575 struct list_head frag_list;
577 /* This points to the sk_buff containing the actual data. */
581 /* In case of GSO packets, this will store the head one */
582 struct sk_buff *head_skb;
583 /* In case of auth enabled, this will point to the shkey */
584 struct sctp_shared_key *shkey;
587 /* These are the SCTP headers by reverse order in a packet.
588 * Note that some of these may happen more than once. In that
589 * case, we point at the "current" one, whatever that means
590 * for that level of header.
593 /* We point this at the FIRST TLV parameter to chunk_hdr. */
594 union sctp_params param_hdr;
597 struct sctp_datahdr *data_hdr;
598 struct sctp_inithdr *init_hdr;
599 struct sctp_sackhdr *sack_hdr;
600 struct sctp_heartbeathdr *hb_hdr;
601 struct sctp_sender_hb_info *hbs_hdr;
602 struct sctp_shutdownhdr *shutdown_hdr;
603 struct sctp_signed_cookie *cookie_hdr;
604 struct sctp_ecnehdr *ecne_hdr;
605 struct sctp_cwrhdr *ecn_cwr_hdr;
606 struct sctp_errhdr *err_hdr;
607 struct sctp_addiphdr *addip_hdr;
608 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
609 struct sctp_authhdr *auth_hdr;
610 struct sctp_idatahdr *idata_hdr;
611 struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
616 struct sctp_chunkhdr *chunk_hdr;
617 struct sctphdr *sctp_hdr;
619 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
620 struct sctp_sndrcvinfo sinfo;
622 /* Which association does this belong to? */
623 struct sctp_association *asoc;
625 /* What endpoint received this chunk? */
626 struct sctp_ep_common *rcvr;
628 /* We fill this in if we are calculating RTT. */
629 unsigned long sent_at;
631 /* What is the origin IP address for this chunk? */
632 union sctp_addr source;
633 /* Destination address for this chunk. */
634 union sctp_addr dest;
636 /* For outbound message, track all fragments for SEND_FAILED. */
637 struct sctp_datamsg *msg;
639 /* For an inbound chunk, this tells us where it came from.
640 * For an outbound chunk, it tells us where we'd like it to
641 * go. It is NULL if we have no preference.
643 struct sctp_transport *transport;
645 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
646 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
647 * spec violates the principle premis that all chunks are processed
650 struct sk_buff *auth_chunk;
652 #define SCTP_CAN_FRTX 0x0
653 #define SCTP_NEED_FRTX 0x1
654 #define SCTP_DONT_FRTX 0x2
655 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
656 has_tsn:1, /* Does this chunk have a TSN yet? */
657 has_ssn:1, /* Does this chunk have a SSN yet? */
658 #define has_mid has_ssn
659 singleton:1, /* Only chunk in the packet? */
660 end_of_packet:1, /* Last chunk in the packet? */
661 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
662 pdiscard:1, /* Discard the whole packet now? */
663 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
664 data_accepted:1, /* At least 1 chunk accepted */
665 auth:1, /* IN: was auth'ed | OUT: needs auth */
666 has_asconf:1, /* IN: have seen an asconf before */
667 tsn_missing_report:2, /* Data chunk missing counter. */
668 fast_retransmit:2; /* Is this chunk fast retransmitted? */
671 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
672 void sctp_chunk_hold(struct sctp_chunk *);
673 void sctp_chunk_put(struct sctp_chunk *);
674 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
675 struct iov_iter *from);
676 void sctp_chunk_free(struct sctp_chunk *);
677 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
678 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
679 const struct sctp_association *,
680 struct sock *, gfp_t gfp);
681 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
683 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
685 static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
687 return ntohs(ch->subh.data_hdr->stream);
691 SCTP_ADDR_NEW, /* new address added to assoc/ep */
692 SCTP_ADDR_SRC, /* address can be used as source */
693 SCTP_ADDR_DEL, /* address about to be deleted */
696 /* This is a structure for holding either an IPv6 or an IPv4 address. */
697 struct sctp_sockaddr_entry {
698 struct list_head list;
705 #define SCTP_ADDRESS_TICK_DELAY 500
707 /* This structure holds lists of chunks as we are assembling for
711 /* These are the SCTP header values (host order) for the packet. */
713 __u16 destination_port;
716 /* This contains the payload chunks. */
717 struct list_head chunk_list;
719 /* This is the overhead of the sctp and ip headers. */
721 /* This is the total size of all chunks INCLUDING padding. */
723 /* This is the maximum size this packet may have */
726 /* The packet is destined for this transport address.
727 * The function we finally use to pass down to the next lower
728 * layer lives in the transport structure.
730 struct sctp_transport *transport;
732 /* pointer to the auth chunk for this packet */
733 struct sctp_chunk *auth;
735 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
736 has_sack:1, /* This packet contains a SACK chunk. */
737 has_auth:1, /* This packet contains an AUTH chunk */
738 has_data:1, /* This packet contains at least 1 DATA chunk */
739 ipfragok:1; /* So let ip fragment this packet */
742 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
743 __u16 sport, __u16 dport);
744 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
745 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
746 struct sctp_chunk *chunk,
747 int one_packet, gfp_t gfp);
748 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
749 struct sctp_chunk *chunk);
750 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
751 void sctp_packet_free(struct sctp_packet *);
753 static inline int sctp_packet_empty(struct sctp_packet *packet)
755 return packet->size == packet->overhead;
758 /* This represents a remote transport address.
759 * For local transport addresses, we just use union sctp_addr.
761 * RFC2960 Section 1.4 Key Terms
763 * o Transport address: A Transport Address is traditionally defined
764 * by Network Layer address, Transport Layer protocol and Transport
765 * Layer port number. In the case of SCTP running over IP, a
766 * transport address is defined by the combination of an IP address
767 * and an SCTP port number (where SCTP is the Transport protocol).
769 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
771 * o The sender keeps a separate congestion control parameter set for
772 * each of the destination addresses it can send to (not each
773 * source-destination pair but for each destination). The parameters
774 * should decay if the address is not used for a long enough time
778 struct sctp_transport {
779 /* A list of transports. */
780 struct list_head transports;
781 struct rhlist_head node;
783 /* Reference counting. */
785 /* RTO-Pending : A flag used to track if one of the DATA
786 * chunks sent to this address is currently being
787 * used to compute a RTT. If this flag is 0,
788 * the next DATA chunk sent to this destination
789 * should be used to compute a RTT and this flag
790 * should be set. Every time the RTT
791 * calculation completes (i.e. the DATA chunk
792 * is SACK'd) clear this flag.
797 * hb_sent : a flag that signals that we have a pending
802 /* Is the Path MTU update pending on this tranport */
805 dst_pending_confirm:1, /* need to confirm neighbour */
807 /* Has this transport moved the ctsn since we last sacked */
813 /* This is the peer's IP address and port. */
814 union sctp_addr ipaddr;
816 /* These are the functions we call to handle LLP stuff. */
817 struct sctp_af *af_specific;
819 /* Which association do we belong to? */
820 struct sctp_association *asoc;
824 * 12.3 Per Transport Address Data
826 * For each destination transport address in the peer's
827 * address list derived from the INIT or INIT ACK chunk, a
828 * number of data elements needs to be maintained including:
830 /* RTO : The current retransmission timeout value. */
833 __u32 rtt; /* This is the most recent RTT. */
835 /* RTTVAR : The current RTT variation. */
838 /* SRTT : The current smoothed round trip time. */
842 * These are the congestion stats.
844 /* cwnd : The current congestion window. */
845 __u32 cwnd; /* This is the actual cwnd. */
847 /* ssthresh : The current slow start threshold value. */
850 /* partial : The tracking method for increase of cwnd when in
851 * bytes acked : congestion avoidance mode (see Section 6.2.2)
853 __u32 partial_bytes_acked;
855 /* Data that has been sent, but not acknowledged. */
858 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
861 struct dst_entry *dst;
862 /* Source address. */
863 union sctp_addr saddr;
865 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
866 * the destination address every heartbeat interval.
868 unsigned long hbinterval;
870 /* SACK delay timeout */
871 unsigned long sackdelay;
874 /* When was the last time that we heard from this transport? We use
875 * this to pick new active and retran paths.
877 ktime_t last_time_heard;
879 /* When was the last time that we sent a chunk using this
880 * transport? We use this to check for idle transports
882 unsigned long last_time_sent;
884 /* Last time(in jiffies) when cwnd is reduced due to the congestion
885 * indication based on ECNE chunk.
887 unsigned long last_time_ecne_reduced;
889 /* This is the max_retrans value for the transport and will
890 * be initialized from the assocs value. This can be changed
891 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
895 /* This is the partially failed retrans value for the transport
896 * and will be initialized from the assocs value. This can be changed
897 * using the SCTP_PEER_ADDR_THLDS socket option
900 /* PMTU : The current known path MTU. */
903 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
906 /* The number of times INIT has been sent on this transport. */
909 /* state : The current state of this destination,
910 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
914 /* These are the error stats for this destination. */
916 /* Error count : The current error count for this destination. */
917 unsigned short error_count;
919 /* Per : A timer used by each destination.
923 * [Everywhere else in the text this is called T3-rtx. -ed]
925 struct timer_list T3_rtx_timer;
927 /* Heartbeat timer is per destination. */
928 struct timer_list hb_timer;
930 /* Timer to handle ICMP proto unreachable envets */
931 struct timer_list proto_unreach_timer;
933 /* Timer to handler reconf chunk rtx */
934 struct timer_list reconf_timer;
936 /* Since we're using per-destination retransmission timers
937 * (see above), we're also using per-destination "transmitted"
938 * queues. This probably ought to be a private struct
939 * accessible only within the outqueue, but it's not, yet.
941 struct list_head transmitted;
943 /* We build bundle-able packets for this transport here. */
944 struct sctp_packet packet;
946 /* This is the list of transports that have chunks to send. */
947 struct list_head send_ready;
949 /* State information saved for SFR_CACC algorithm. The key
950 * idea in SFR_CACC is to maintain state at the sender on a
951 * per-destination basis when a changeover happens.
952 * char changeover_active;
953 * char cycling_changeover;
954 * __u32 next_tsn_at_change;
955 * char cacc_saw_newack;
958 /* An unsigned integer, which stores the next TSN to be
959 * used by the sender, at the moment of changeover.
961 __u32 next_tsn_at_change;
963 /* A flag which indicates the occurrence of a changeover */
964 char changeover_active;
966 /* A flag which indicates whether the change of primary is
967 * the first switch to this destination address during an
970 char cycling_changeover;
972 /* A temporary flag, which is used during the processing of
973 * a SACK to estimate the causative TSN(s)'s group.
975 char cacc_saw_newack;
978 /* 64-bit random number sent with heartbeat. */
984 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
986 void sctp_transport_set_owner(struct sctp_transport *,
987 struct sctp_association *);
988 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
990 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
991 void sctp_transport_free(struct sctp_transport *);
992 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
993 void sctp_transport_reset_hb_timer(struct sctp_transport *);
994 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
995 int sctp_transport_hold(struct sctp_transport *);
996 void sctp_transport_put(struct sctp_transport *);
997 void sctp_transport_update_rto(struct sctp_transport *, __u32);
998 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
999 void sctp_transport_lower_cwnd(struct sctp_transport *t,
1000 enum sctp_lower_cwnd reason);
1001 void sctp_transport_burst_limited(struct sctp_transport *);
1002 void sctp_transport_burst_reset(struct sctp_transport *);
1003 unsigned long sctp_transport_timeout(struct sctp_transport *);
1004 void sctp_transport_reset(struct sctp_transport *t);
1005 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1006 void sctp_transport_immediate_rtx(struct sctp_transport *);
1007 void sctp_transport_dst_release(struct sctp_transport *t);
1008 void sctp_transport_dst_confirm(struct sctp_transport *t);
1011 /* This is the structure we use to queue packets as they come into
1012 * SCTP. We write packets to it and read chunks from it.
1015 /* This is actually a queue of sctp_chunk each
1016 * containing a partially decoded packet.
1018 struct list_head in_chunk_list;
1019 /* This is the packet which is currently off the in queue and is
1020 * being worked on through the inbound chunk processing.
1022 struct sctp_chunk *in_progress;
1024 /* This is the delayed task to finish delivering inbound
1027 struct work_struct immediate;
1030 void sctp_inq_init(struct sctp_inq *);
1031 void sctp_inq_free(struct sctp_inq *);
1032 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1033 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1034 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1035 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1037 /* This is the structure we use to hold outbound chunks. You push
1038 * chunks in and they automatically pop out the other end as bundled
1039 * packets (it calls (*output_handler)()).
1041 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1042 * and 8.2 of the v13 draft.
1044 * It handles retransmissions. The connection to the timeout portion
1045 * of the state machine is through sctp_..._timeout() and timeout_handler.
1047 * If you feed it SACKs, it will eat them.
1049 * If you give it big chunks, it will fragment them.
1051 * It assigns TSN's to data chunks. This happens at the last possible
1052 * instant before transmission.
1054 * When free()'d, it empties itself out via output_handler().
1057 struct sctp_association *asoc;
1059 /* Data pending that has never been transmitted. */
1060 struct list_head out_chunk_list;
1062 /* Stream scheduler being used */
1063 struct sctp_sched_ops *sched;
1065 unsigned int out_qlen; /* Total length of queued data chunks. */
1067 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1070 /* These are control chunks we want to send. */
1071 struct list_head control_chunk_list;
1073 /* These are chunks that have been sacked but are above the
1074 * CTSN, or cumulative tsn ack point.
1076 struct list_head sacked;
1078 /* Put chunks on this list to schedule them for
1081 struct list_head retransmit;
1083 /* Put chunks on this list to save them for FWD TSN processing as
1084 * they were abandoned.
1086 struct list_head abandoned;
1088 /* How many unackd bytes do we have in-flight? */
1089 __u32 outstanding_bytes;
1091 /* Are we doing fast-rtx on this queue */
1098 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1099 void sctp_outq_teardown(struct sctp_outq *);
1100 void sctp_outq_free(struct sctp_outq*);
1101 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1102 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1103 int sctp_outq_is_empty(const struct sctp_outq *);
1104 void sctp_outq_restart(struct sctp_outq *);
1106 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1107 enum sctp_retransmit_reason reason);
1108 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1109 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1110 void sctp_prsctp_prune(struct sctp_association *asoc,
1111 struct sctp_sndrcvinfo *sinfo, int msg_len);
1112 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1113 /* Uncork and flush an outqueue. */
1114 static inline void sctp_outq_cork(struct sctp_outq *q)
1119 /* SCTP skb control block.
1120 * sctp_input_cb is currently used on rx and sock rx queue
1122 struct sctp_input_cb {
1124 struct inet_skb_parm h4;
1125 #if IS_ENABLED(CONFIG_IPV6)
1126 struct inet6_skb_parm h6;
1129 struct sctp_chunk *chunk;
1132 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1134 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1136 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1138 return chunk->head_skb ? : skb;
1141 /* These bind address data fields common between endpoints and associations */
1142 struct sctp_bind_addr {
1144 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1146 * SCTP Port: The local SCTP port number the endpoint is
1151 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1153 * Address List: The list of IP addresses that this instance
1154 * has bound. This information is passed to one's
1155 * peer(s) in INIT and INIT ACK chunks.
1157 struct list_head address_list;
1160 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1161 void sctp_bind_addr_free(struct sctp_bind_addr *);
1162 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1163 const struct sctp_bind_addr *src,
1164 enum sctp_scope scope, gfp_t gfp,
1166 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1167 const struct sctp_bind_addr *src,
1169 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1170 int new_size, __u8 addr_state, gfp_t gfp);
1171 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1172 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1173 struct sctp_sock *);
1174 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1175 struct sctp_sock *, struct sctp_sock *);
1176 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1177 const union sctp_addr *addr);
1178 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1179 const union sctp_addr *addrs,
1181 struct sctp_sock *opt);
1182 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1185 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1186 __u16 port, gfp_t gfp);
1188 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1189 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1190 const enum sctp_scope scope);
1191 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1192 int sctp_is_ep_boundall(struct sock *sk);
1195 /* What type of endpoint? */
1196 enum sctp_endpoint_type {
1197 SCTP_EP_TYPE_SOCKET,
1198 SCTP_EP_TYPE_ASSOCIATION,
1202 * A common base class to bridge the implmentation view of a
1203 * socket (usually listening) endpoint versus an association's
1205 * This common structure is useful for several purposes:
1206 * 1) Common interface for lookup routines.
1207 * a) Subfunctions work for either endpoint or association
1208 * b) Single interface to lookup allows hiding the lookup lock rather
1209 * than acquiring it externally.
1210 * 2) Common interface for the inbound chunk handling/state machine.
1211 * 3) Common object handling routines for reference counting, etc.
1212 * 4) Disentangle association lookup from endpoint lookup, where we
1213 * do not have to find our endpoint to find our association.
1217 struct sctp_ep_common {
1218 /* Fields to help us manage our entries in the hash tables. */
1219 struct hlist_node node;
1222 /* Runtime type information. What kind of endpoint is this? */
1223 enum sctp_endpoint_type type;
1225 /* Some fields to help us manage this object.
1226 * refcnt - Reference count access to this object.
1227 * dead - Do not attempt to use this object.
1232 /* What socket does this endpoint belong to? */
1235 /* This is where we receive inbound chunks. */
1236 struct sctp_inq inqueue;
1238 /* This substructure includes the defining parameters of the
1240 * bind_addr.port is our shared port number.
1241 * bind_addr.address_list is our set of local IP addresses.
1243 struct sctp_bind_addr bind_addr;
1247 /* RFC Section 1.4 Key Terms
1249 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1250 * multi-homed host, an SCTP endpoint is represented to its peers as a
1251 * combination of a set of eligible destination transport addresses to
1252 * which SCTP packets can be sent and a set of eligible source
1253 * transport addresses from which SCTP packets can be received.
1254 * All transport addresses used by an SCTP endpoint must use the
1255 * same port number, but can use multiple IP addresses. A transport
1256 * address used by an SCTP endpoint must not be used by another
1257 * SCTP endpoint. In other words, a transport address is unique
1258 * to an SCTP endpoint.
1260 * From an implementation perspective, each socket has one of these.
1261 * A TCP-style socket will have exactly one association on one of
1262 * these. An UDP-style socket will have multiple associations hanging
1266 struct sctp_endpoint {
1267 /* Common substructure for endpoint and association. */
1268 struct sctp_ep_common base;
1270 /* Associations: A list of current associations and mappings
1271 * to the data consumers for each association. This
1272 * may be in the form of a hash table or other
1273 * implementation dependent structure. The data
1274 * consumers may be process identification
1275 * information such as file descriptors, named pipe
1276 * pointer, or table pointers dependent on how SCTP
1279 /* This is really a list of struct sctp_association entries. */
1280 struct list_head asocs;
1282 /* Secret Key: A secret key used by this endpoint to compute
1283 * the MAC. This SHOULD be a cryptographic quality
1284 * random number with a sufficient length.
1285 * Discussion in [RFC1750] can be helpful in
1286 * selection of the key.
1288 __u8 secret_key[SCTP_SECRET_SIZE];
1290 /* digest: This is a digest of the sctp cookie. This field is
1291 * only used on the receive path when we try to validate
1292 * that the cookie has not been tampered with. We put
1293 * this here so we pre-allocate this once and can re-use
1298 /* sendbuf acct. policy. */
1299 __u32 sndbuf_policy;
1301 /* rcvbuf acct. policy. */
1302 __u32 rcvbuf_policy;
1304 /* SCTP AUTH: array of the HMACs that will be allocated
1305 * we need this per association so that we don't serialize
1307 struct crypto_shash **auth_hmacs;
1309 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1310 struct sctp_hmac_algo_param *auth_hmacs_list;
1312 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1313 struct sctp_chunks_param *auth_chunk_list;
1315 /* SCTP-AUTH: endpoint shared keys */
1316 struct list_head endpoint_shared_keys;
1317 __u16 active_key_id;
1322 __u8 strreset_enable;
1325 /* Recover the outter endpoint structure. */
1326 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1328 struct sctp_endpoint *ep;
1330 ep = container_of(base, struct sctp_endpoint, base);
1334 /* These are function signatures for manipulating endpoints. */
1335 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1336 void sctp_endpoint_free(struct sctp_endpoint *);
1337 void sctp_endpoint_put(struct sctp_endpoint *);
1338 void sctp_endpoint_hold(struct sctp_endpoint *);
1339 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1340 struct sctp_association *sctp_endpoint_lookup_assoc(
1341 const struct sctp_endpoint *ep,
1342 const union sctp_addr *paddr,
1343 struct sctp_transport **);
1344 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1345 const union sctp_addr *);
1346 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1347 struct net *, const union sctp_addr *);
1348 int sctp_has_association(struct net *net, const union sctp_addr *laddr,
1349 const union sctp_addr *paddr);
1351 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1352 const struct sctp_association *asoc,
1353 enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1354 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1355 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1356 const union sctp_addr *peer,
1357 struct sctp_init_chunk *init, gfp_t gfp);
1358 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1359 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1361 struct sctp_inithdr_host {
1364 __u16 num_outbound_streams;
1365 __u16 num_inbound_streams;
1369 struct sctp_stream_priorities {
1370 /* List of priorities scheduled */
1371 struct list_head prio_sched;
1372 /* List of streams scheduled */
1373 struct list_head active;
1374 /* The next stream stream in line */
1375 struct sctp_stream_out_ext *next;
1379 struct sctp_stream_out_ext {
1380 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1381 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1382 struct list_head outq; /* chunks enqueued by this stream */
1385 /* Scheduled streams list */
1386 struct list_head prio_list;
1387 struct sctp_stream_priorities *prio_head;
1389 /* Fields used by RR scheduler */
1391 struct list_head rr_list;
1396 struct sctp_stream_out {
1402 struct sctp_stream_out_ext *ext;
1406 struct sctp_stream_in {
1418 struct sctp_stream {
1419 struct sctp_stream_out *out;
1420 struct sctp_stream_in *in;
1423 /* Current stream being sent, if any */
1424 struct sctp_stream_out *out_curr;
1426 /* Fields used by priority scheduler */
1428 /* List of priorities scheduled */
1429 struct list_head prio_list;
1431 /* Fields used by RR scheduler */
1433 /* List of streams scheduled */
1434 struct list_head rr_list;
1435 /* The next stream stream in line */
1436 struct sctp_stream_out_ext *rr_next;
1439 struct sctp_stream_interleave *si;
1442 #define SCTP_STREAM_CLOSED 0x00
1443 #define SCTP_STREAM_OPEN 0x01
1445 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1447 return stream->si->data_chunk_len;
1450 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1452 return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1455 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1457 return stream->si->ftsn_chunk_len;
1460 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1462 return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1465 /* SCTP_GET_ASSOC_STATS counters */
1466 struct sctp_priv_assoc_stats {
1467 /* Maximum observed rto in the association during subsequent
1468 * observations. Value is set to 0 if no RTO measurement took place
1469 * The transport where the max_rto was observed is returned in
1472 struct sockaddr_storage obs_rto_ipaddr;
1474 /* Total In and Out SACKs received and sent */
1477 /* Total In and Out packets received and sent */
1480 /* Total retransmitted chunks */
1482 /* TSN received > next expected */
1484 /* Duplicate Chunks received */
1486 /* Gap Ack Blocks received */
1488 /* Unordered data chunks sent and received */
1491 /* Ordered data chunks sent and received */
1494 /* Control chunks sent and received */
1501 * 12. Recommended Transmission Control Block (TCB) Parameters
1503 * This section details a recommended set of parameters that should
1504 * be contained within the TCB for an implementation. This section is
1505 * for illustrative purposes and should not be deemed as requirements
1506 * on an implementation or as an exhaustive list of all parameters
1507 * inside an SCTP TCB. Each implementation may need its own additional
1508 * parameters for optimization.
1512 /* Here we have information about each individual association. */
1513 struct sctp_association {
1515 /* A base structure common to endpoint and association.
1516 * In this context, it represents the associations's view
1517 * of the local endpoint of the association.
1519 struct sctp_ep_common base;
1521 /* Associations on the same socket. */
1522 struct list_head asocs;
1524 /* association id. */
1525 sctp_assoc_t assoc_id;
1527 /* This is our parent endpoint. */
1528 struct sctp_endpoint *ep;
1530 /* These are those association elements needed in the cookie. */
1531 struct sctp_cookie c;
1533 /* This is all information about our peer. */
1535 /* transport_addr_list
1537 * Peer : A list of SCTP transport addresses that the
1538 * Transport : peer is bound to. This information is derived
1539 * Address : from the INIT or INIT ACK and is used to
1540 * List : associate an inbound packet with a given
1541 * : association. Normally this information is
1542 * : hashed or keyed for quick lookup and access
1544 * : The list is also initialized with the list
1545 * : of addresses passed with the sctp_connectx()
1548 * It is a list of SCTP_transport's.
1550 struct list_head transport_addr_list;
1554 * Peer Rwnd : Current calculated value of the peer's rwnd.
1560 * Peer : A count of the number of peer addresses
1561 * Transport : in the Peer Transport Address List.
1565 __u16 transport_count;
1568 * The transport layer port number.
1574 * Primary : This is the current primary destination
1575 * Path : transport address of the peer endpoint. It
1576 * : may also specify a source transport address
1577 * : on this endpoint.
1579 * All of these paths live on transport_addr_list.
1581 * At the bakeoffs, we discovered that the intent of
1582 * primaryPath is that it only changes when the ULP
1583 * asks to have it changed. We add the activePath to
1584 * designate the connection we are currently using to
1585 * transmit new data and most control chunks.
1587 struct sctp_transport *primary_path;
1589 /* Cache the primary path address here, when we
1590 * need a an address for msg_name.
1592 union sctp_addr primary_addr;
1595 * The path that we are currently using to
1596 * transmit new data and most control chunks.
1598 struct sctp_transport *active_path;
1602 * RFC2960 6.4 Multi-homed SCTP Endpoints
1604 * Furthermore, when its peer is multi-homed, an
1605 * endpoint SHOULD try to retransmit a chunk to an
1606 * active destination transport address that is
1607 * different from the last destination address to
1608 * which the DATA chunk was sent.
1610 struct sctp_transport *retran_path;
1612 /* Pointer to last transport I have sent on. */
1613 struct sctp_transport *last_sent_to;
1615 /* This is the last transport I have received DATA on. */
1616 struct sctp_transport *last_data_from;
1619 * Mapping An array of bits or bytes indicating which out of
1620 * Array order TSN's have been received (relative to the
1621 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1622 * order packets have been received, this array
1623 * will be set to all zero. This structure may be
1624 * in the form of a circular buffer or bit array.
1626 * Last Rcvd : This is the last TSN received in
1627 * TSN : sequence. This value is set initially by
1628 * : taking the peer's Initial TSN, received in
1629 * : the INIT or INIT ACK chunk, and subtracting
1632 * Throughout most of the specification this is called the
1633 * "Cumulative TSN ACK Point". In this case, we
1634 * ignore the advice in 12.2 in favour of the term
1635 * used in the bulk of the text. This value is hidden
1636 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1638 struct sctp_tsnmap tsn_map;
1640 /* This mask is used to disable sending the ASCONF chunk
1641 * with specified parameter to peer.
1643 __be16 addip_disabled_mask;
1645 /* These are capabilities which our peer advertised. */
1646 __u8 ecn_capable:1, /* Can peer do ECN? */
1647 ipv4_address:1, /* Peer understands IPv4 addresses? */
1648 ipv6_address:1, /* Peer understands IPv6 addresses? */
1649 hostname_address:1, /* Peer understands DNS addresses? */
1650 asconf_capable:1, /* Does peer support ADDIP? */
1651 prsctp_capable:1, /* Can peer do PR-SCTP? */
1652 reconf_capable:1, /* Can peer do RE-CONFIG? */
1653 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1655 /* sack_needed : This flag indicates if the next received
1656 * : packet is to be responded to with a
1657 * : SACK. This is initialized to 0. When a packet
1658 * : is received sack_cnt is incremented. If this value
1659 * : reaches 2 or more, a SACK is sent and the
1660 * : value is reset to 0. Note: This is used only
1661 * : when no DATA chunks are received out of
1662 * : order. When DATA chunks are out of order,
1663 * : SACK's are not delayed (see Section 6).
1665 __u8 sack_needed:1, /* Do we need to sack the peer? */
1667 zero_window_announced:1;
1670 __u32 adaptation_ind; /* Adaptation Code point. */
1672 struct sctp_inithdr_host i;
1676 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1677 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1678 * Initial TSN Value minus 1
1682 /* SCTP-AUTH: We need to know pears random number, hmac list
1683 * and authenticated chunk list. All that is part of the
1684 * cookie and these are just pointers to those locations
1686 struct sctp_random_param *peer_random;
1687 struct sctp_chunks_param *peer_chunks;
1688 struct sctp_hmac_algo_param *peer_hmacs;
1691 /* State : A state variable indicating what state the
1692 * : association is in, i.e. COOKIE-WAIT,
1693 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1694 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1696 * Note: No "CLOSED" state is illustrated since if a
1697 * association is "CLOSED" its TCB SHOULD be removed.
1699 * In this implementation we DO have a CLOSED
1700 * state which is used during initiation and shutdown.
1702 * State takes values from SCTP_STATE_*.
1704 enum sctp_state state;
1706 /* Overall : The overall association error count.
1707 * Error Count : [Clear this any time I get something.]
1709 int overall_error_count;
1711 /* The cookie life I award for any cookie. */
1712 ktime_t cookie_life;
1714 /* These are the association's initial, max, and min RTO values.
1715 * These values will be initialized by system defaults, but can
1716 * be modified via the SCTP_RTOINFO socket option.
1718 unsigned long rto_initial;
1719 unsigned long rto_max;
1720 unsigned long rto_min;
1722 /* Maximum number of new data packets that can be sent in a burst. */
1725 /* This is the max_retrans value for the association. This value will
1726 * be initialized initialized from system defaults, but can be
1727 * modified by the SCTP_ASSOCINFO socket option.
1731 /* This is the partially failed retrans value for the transport
1732 * and will be initialized from the assocs value. This can be
1733 * changed using the SCTP_PEER_ADDR_THLDS socket option
1737 /* Maximum number of times the endpoint will retransmit INIT */
1738 __u16 max_init_attempts;
1740 /* How many times have we resent an INIT? */
1743 /* The largest timeout or RTO value to use in attempting an INIT */
1744 unsigned long max_init_timeo;
1746 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1747 * the destination address every heartbeat interval. This value
1748 * will be inherited by all new transports.
1750 unsigned long hbinterval;
1752 /* This is the max_retrans value for new transports in the
1757 /* Flag that path mtu update is pending */
1760 /* Association : The smallest PMTU discovered for all of the
1761 * PMTU : peer's transport addresses.
1765 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1769 /* SACK delay timeout */
1770 unsigned long sackdelay;
1772 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1773 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1775 /* Transport to which SHUTDOWN chunk was last sent. */
1776 struct sctp_transport *shutdown_last_sent_to;
1778 /* Transport to which INIT chunk was last sent. */
1779 struct sctp_transport *init_last_sent_to;
1781 /* How many times have we resent a SHUTDOWN */
1782 int shutdown_retries;
1784 /* Next TSN : The next TSN number to be assigned to a new
1785 * : DATA chunk. This is sent in the INIT or INIT
1786 * : ACK chunk to the peer and incremented each
1787 * : time a DATA chunk is assigned a TSN
1788 * : (normally just prior to transmit or during
1794 * Last Rcvd : This is the last TSN received in sequence. This value
1795 * TSN : is set initially by taking the peer's Initial TSN,
1796 * : received in the INIT or INIT ACK chunk, and
1797 * : subtracting one from it.
1799 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1802 __u32 ctsn_ack_point;
1804 /* PR-SCTP Advanced.Peer.Ack.Point */
1805 __u32 adv_peer_ack_point;
1807 /* Highest TSN that is acknowledged by incoming SACKs. */
1808 __u32 highest_sacked;
1810 /* TSN marking the fast recovery exit point */
1811 __u32 fast_recovery_exit;
1813 /* Flag to track the current fast recovery state */
1816 /* The number of unacknowledged data chunks. Reported through
1817 * the SCTP_STATUS sockopt.
1821 /* The total number of data chunks that we've had to retransmit
1822 * as the result of a T3 timer expiration
1824 __u32 rtx_data_chunks;
1826 /* This is the association's receive buffer space. This value is used
1827 * to set a_rwnd field in an INIT or a SACK chunk.
1831 /* This is the last advertised value of rwnd over a SACK chunk. */
1834 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1835 * to slop over a maximum of the association's frag_point.
1839 /* Keeps treack of rwnd pressure. This happens when we have
1840 * a window, but not recevie buffer (i.e small packets). This one
1841 * is releases slowly (1 PMTU at a time ).
1845 /* This is the sndbuf size in use for the association.
1846 * This corresponds to the sndbuf size for the association,
1847 * as specified in the sk->sndbuf.
1851 /* This is the amount of memory that this association has allocated
1852 * in the receive path at any given time.
1854 atomic_t rmem_alloc;
1856 /* This is the wait queue head for send requests waiting on
1857 * the association sndbuf space.
1859 wait_queue_head_t wait;
1861 /* The message size at which SCTP fragmentation will occur. */
1865 /* Counter used to count INIT errors. */
1866 int init_err_counter;
1868 /* Count the number of INIT cycles (for doubling timeout). */
1871 /* Default send parameters. */
1872 __u16 default_stream;
1873 __u16 default_flags;
1875 __u32 default_context;
1876 __u32 default_timetolive;
1878 /* Default receive parameters */
1879 __u32 default_rcv_context;
1882 struct sctp_stream stream;
1884 /* All outbound chunks go through this structure. */
1885 struct sctp_outq outqueue;
1887 /* A smart pipe that will handle reordering and fragmentation,
1888 * as well as handle passing events up to the ULP.
1890 struct sctp_ulpq ulpq;
1892 /* Last TSN that caused an ECNE Chunk to be sent. */
1893 __u32 last_ecne_tsn;
1895 /* Last TSN that caused a CWR Chunk to be sent. */
1898 /* How many duplicated TSNs have we seen? */
1901 /* These are to support
1902 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1903 * and Enforcement of Flow and Message Limits"
1904 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1905 * or "ADDIP" for short.
1910 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1912 * R1) One and only one ASCONF Chunk MAY be in transit and
1913 * unacknowledged at any one time. If a sender, after sending
1914 * an ASCONF chunk, decides it needs to transfer another
1915 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1916 * returns from the previous ASCONF Chunk before sending a
1917 * subsequent ASCONF. Note this restriction binds each side,
1918 * so at any time two ASCONF may be in-transit on any given
1919 * association (one sent from each endpoint).
1921 * [This is our one-and-only-one ASCONF in flight. If we do
1922 * not have an ASCONF in flight, this is NULL.]
1924 struct sctp_chunk *addip_last_asconf;
1926 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1928 * This is needed to implement itmes E1 - E4 of the updated
1929 * spec. Here is the justification:
1931 * Since the peer may bundle multiple ASCONF chunks toward us,
1932 * we now need the ability to cache multiple ACKs. The section
1933 * describes in detail how they are cached and cleaned up.
1935 struct list_head asconf_ack_list;
1937 /* These ASCONF chunks are waiting to be sent.
1939 * These chunaks can't be pushed to outqueue until receiving
1940 * ASCONF_ACK for the previous ASCONF indicated by
1941 * addip_last_asconf, so as to guarantee that only one ASCONF
1942 * is in flight at any time.
1944 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1946 * In defining the ASCONF Chunk transfer procedures, it is
1947 * essential that these transfers MUST NOT cause congestion
1948 * within the network. To achieve this, we place these
1949 * restrictions on the transfer of ASCONF Chunks:
1951 * R1) One and only one ASCONF Chunk MAY be in transit and
1952 * unacknowledged at any one time. If a sender, after sending
1953 * an ASCONF chunk, decides it needs to transfer another
1954 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1955 * returns from the previous ASCONF Chunk before sending a
1956 * subsequent ASCONF. Note this restriction binds each side,
1957 * so at any time two ASCONF may be in-transit on any given
1958 * association (one sent from each endpoint).
1961 * [I really think this is EXACTLY the sort of intelligence
1962 * which already resides in sctp_outq. Please move this
1963 * queue and its supporting logic down there. --piggy]
1965 struct list_head addip_chunk_list;
1967 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1969 * A2) A serial number should be assigned to the Chunk. The
1970 * serial number SHOULD be a monotonically increasing
1971 * number. The serial number SHOULD be initialized at
1972 * the start of the association to the same value as the
1973 * Initial TSN and every time a new ASCONF chunk is created
1974 * it is incremented by one after assigning the serial number
1975 * to the newly created chunk.
1978 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1980 * Serial Number : 32 bits (unsigned integer)
1982 * This value represents a Serial Number for the ASCONF
1983 * Chunk. The valid range of Serial Number is from 0 to
1984 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1985 * after reaching 4294967295.
1988 int src_out_of_asoc_ok;
1989 union sctp_addr *asconf_addr_del_pending;
1990 struct sctp_transport *new_transport;
1992 /* SCTP AUTH: list of the endpoint shared keys. These
1993 * keys are provided out of band by the user applicaton
1994 * and can't change during the lifetime of the association
1996 struct list_head endpoint_shared_keys;
1999 * The current generated assocaition shared key (secret)
2001 struct sctp_auth_bytes *asoc_shared_key;
2002 struct sctp_shared_key *shkey;
2004 /* SCTP AUTH: hmac id of the first peer requested algorithm
2007 __u16 default_hmac_id;
2009 __u16 active_key_id;
2011 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
2012 temp:1, /* Is it a temporary association? */
2018 __u8 strreset_enable;
2019 __u8 strreset_outstanding; /* request param count on the fly */
2021 __u32 strreset_outseq; /* Update after receiving response */
2022 __u32 strreset_inseq; /* Update after receiving request */
2023 __u32 strreset_result[2]; /* save the results of last 2 responses */
2025 struct sctp_chunk *strreset_chunk; /* save request chunk */
2027 struct sctp_priv_assoc_stats stats;
2029 int sent_cnt_removable;
2031 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2032 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2036 /* An eyecatcher for determining if we are really looking at an
2037 * association data structure.
2040 SCTP_ASSOC_EYECATCHER = 0xa550c123,
2043 /* Recover the outter association structure. */
2044 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2046 struct sctp_association *asoc;
2048 asoc = container_of(base, struct sctp_association, base);
2052 /* These are function signatures for manipulating associations. */
2055 struct sctp_association *
2056 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2057 enum sctp_scope scope, gfp_t gfp);
2058 void sctp_association_free(struct sctp_association *);
2059 void sctp_association_put(struct sctp_association *);
2060 void sctp_association_hold(struct sctp_association *);
2062 struct sctp_transport *sctp_assoc_choose_alter_transport(
2063 struct sctp_association *, struct sctp_transport *);
2064 void sctp_assoc_update_retran_path(struct sctp_association *);
2065 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2066 const union sctp_addr *);
2067 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2068 const union sctp_addr *laddr);
2069 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2070 const union sctp_addr *address,
2072 const int peer_state);
2073 void sctp_assoc_del_peer(struct sctp_association *asoc,
2074 const union sctp_addr *addr);
2075 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2076 struct sctp_transport *peer);
2077 void sctp_assoc_control_transport(struct sctp_association *asoc,
2078 struct sctp_transport *transport,
2079 enum sctp_transport_cmd command,
2080 sctp_sn_error_t error);
2081 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2082 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
2084 const union sctp_addr *,
2085 const union sctp_addr *);
2086 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2087 int sctp_assoc_update(struct sctp_association *old,
2088 struct sctp_association *new);
2090 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2092 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2093 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2094 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2095 void sctp_assoc_set_primary(struct sctp_association *,
2096 struct sctp_transport *);
2097 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2098 struct sctp_transport *);
2099 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2100 enum sctp_scope scope, gfp_t gfp);
2101 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2102 struct sctp_cookie*,
2104 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2105 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2106 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2107 const struct sctp_association *asoc,
2109 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2111 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2112 const union sctp_addr *ss2);
2113 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2115 /* A convenience structure to parse out SCTP specific CMSGs. */
2117 struct sctp_initmsg *init;
2118 struct sctp_sndrcvinfo *srinfo;
2119 struct sctp_sndinfo *sinfo;
2120 struct sctp_prinfo *prinfo;
2121 struct sctp_authinfo *authinfo;
2122 struct msghdr *addrs_msg;
2125 /* Structure for tracking memory objects */
2126 struct sctp_dbg_objcnt_entry {
2131 #endif /* __sctp_structs_h__ */